local modem = peripheral.find("modem", rednet.open);

local rsSidePower = "left"
local rsSideUnclog = "bottom"
local rsSideWaterInput = "right"
local rsSidePotionOutput = "back"

local errorName = "MIXER_CONTROLLER"

-- different protocols used by this program
local logging = "Potion_Brewer_LOGGER"
local mixerControlProtocol = "Potion_Brewer_Mixer_Control_Protocol_id"
local mixerControlProtocolRespond = "Potion_Brewer_Mixer_Control_Protocol_Respond_id"
local mixerRequestUpdate = "Potion_Brewer_Mixer_Request_Update_id"
local mixerRequestUpdateRespond = "Potion_Brewer_Mixer_Request_Update_Respond_id"
local dispenserRequestProtocol = "Potion_Brewer_Dispenser_Request_v001"
local dispenserConfirmProtocol = "Potion_Brewer_Dispenser_Confirm_v001"
local scannerProtocol = "Potion_Brewer_SCANNER"

local timeoutErrorProtocol = "Potion_Brewer_ERROR_PROTOCOL_TIMEOUT"

-- different event names used by this program
local eventScanner = "EVENT_SCANNER_mixer"

local idFilename = "id"
local id = 0

local timeoutTime = 600
local pumpTime = 4
local mixTime = 4

local inUse = false
local error = false

local incomingRequest = nil


function log(string)
    print(string)
    rednet.broadcast("[MIXER_MODULE_"..id.."] "..string, logging)
end

function watchdogTimeout(funcName)
    -- wait for timeout
    sleep(timeoutTime)
    log(funcName.." Timed out! Took longer than " .. timeoutTime .. " seconds!")
    rednet.broadcast(errorName, timeoutErrorProtocol)
    error = true
end

function setPower(enabled)
    redstone.setOutput(rsSidePower, not enabled)
end
function setUnclog(enabled)
    redstone.setOutput(rsSideUnclog, not enabled)
end
function setWaterInput(enabled)
    redstone.setOutput(rsSideWaterInput, not enabled)
end
function setPotionOutput(enabled)
    redstone.setOutput(rsSidePotionOutput, not enabled)
end

function requestItems(request)
    if(request ~= nil and request.data ~= nil and request.data.length ~= nil and request.data.items ~= nil) then

        parallel.waitForAny(
        function()
            log("requesting items")
            request.data.id = id
            rednet.broadcast(request, dispenserRequestProtocol)

            -- count incoming items
            for i = 0,request.data.length,1 do
                rednet.receive(eventScanner .. id)
                log("item received")
            end

            log("all items received")

        end, function()
            watchdogTimeout("requestItems")
        end)
    end
end

function broadcastInfo()
    local response = {}
    response.error = error
    response.inUse = inUse

    local responseMessage = textutils.serialize(response)
    rednet.broadcast(responseMessage, mixerRequestUpdateRespond..id)
end

function errorCheck()
    if error == true then
        log("[ERROR] ERROR ENCOUNTERED!!!")
        error = false
        return true
    end
    return false
end

function init()

    local idFile = fs.open(idFilename, "r")
    if idFile then
        id = tonumber(idFile.readAll())
        idFile.close()
    else
        log("failed to open id file: "..idFilename)
    end

    log("ID file loaded, this mixer is: "..id)
    errorName = "MIXER_CONTROLLER_"..id

    setPower(false)
    setUnclog(false)
    setWaterInput(false)
    setPotionOutput(false)

    parallel.waitForAny(
        function()
            while true do
                if incomingRequest ~= nil then

                    log("processing request: " .. textutils.serialize(incomingRequest))

                    -- power on
                    setPower(true)

                    -- fill with water
                    setWaterInput(true)
                    sleep(pumpTime)
                    setWaterInput(false)

                    -- request items
                    requestItems(incomingRequest)

                    -- wait for mixer to finnish
                    sleep(mixTime)

                    -- drain and unclog
                    setPotionOutput(true)
                    setUnclog(true)
                    sleep(pumpTime)
                    setUnclog(false)
                    setPotionOutput(false)

                    -- power off
                    setPower(false)

                    incomingRequest = nil
                end

                error = false
                sleep(0.2)
            end
        end,
        function()
            while true do
                -- respond to status requests
                rednet.receive(mixerRequestUpdate..id)
                broadcastInfo()
            end
        end,
        function()
            while true do
                local senderID, message = rednet.receive(mixerControlProtocol..id)
                incomingRequest = textutils.unserialize(message)

                broadcastInfo()
            end
        end
    )

end

init()